Comet 3I/ATLAS has rapidly joined the ranks of the most intriguing astronomical events of the decade. Only the third known interstellar object to pass through our Solar System, this comet is offering an unprecedented opportunity for scientists to study material that formed around another star. Since the initial detection on July 1, 2025, a wave of excitement has been building among astronomers, researchers, and space enthusiasts alike as NASA continues to make new images available that have been captured by an amazing array of spacecraft and telescopes spread throughout the Solar System.
Each photo represents a different angle, a different wavelength, and a different scientific perspective on the comet, enlightening new details in its behavior, composition, and journey. As Shawn Domagal-Goldman, NASA’s acting director of the Astrophysics Division, put it, these visuals highlight “how magical the universe could be.”
Discovery and Early Observations
A Rare Interstellar Traveler Enters Our View
Comet 3I/ATLAS was first identified using NASA’s ATLAS Asteroid Terrestrial-impact Last Alert System, a system designed to detect near-Earth objects. What originally seemed like a routine detection quickly became a groundbreaking announcement as astronomers realized the object’s trajectory did not fit the orbit of anything originating within our Solar System.
This hyperbolic path indicated that the comet came from outside of our planetary neighbourhood; it is just the third interstellar visitor confirmed so far, after ‘Oumuamua (1I/2017 U1) and Comet 2I/Borisov.
Few telescopes were positioned at just the right angle or were equipped to produce high-resolution imagery of the comet in the weeks immediately following its discovery. One of the first high-profile images came courtesy of the Hubble Space Telescope on July 21, 2025, when 3I/ATLAS was about 277 million miles from Earth. This early view gave astronomers an initial glimpse at the comet’s brightness, shape, and faint tail structure.
Multi-Mission Collaboration Across the Solar System
A Coordinated Effort by NASA’s Orbiters, Telescopes, and Probes
The unique advantage NASA has today is in the fleet of sophisticated observatories positioned at different points around the Solar System. For Comet 3I/ATLAS, that meant a rare opportunity: the comet was captured by a range of missions with distinct technologies from various angles and distances.
Missions involved include:
- ATLAS telescope
- Hubble Space Telescope
- JWST: James Webb Space Telescope
- TESS – Transiting Exoplanet Survey Satellite
- Swift Observatory
- SPHEREx
- Lucy spacecraft
- Psyche spacecraft
- Parker Solar Probe
- Perseverance rover
- Curiosity rover
- Mars Reconnaissance Orbiter (MRO)
- MAVEN
- Europa Clipper
- PUNCH
- ESA/NASA SOHO & JUICE missions
This unparalleled network allowed scientists to capture views across ultraviolet, visible, infrared, and other wavelengths that gave a far more comprehensive picture of the comet than any single mission could achieve.
JWST and SPHEREx: Unveiling the Comet in Infrared
Detection of Water Ice, Carbon Dioxide, and Hidden Molecular Clues
One of the most scientifically valuable observations came from the James Webb Space Telescope. JWST pointed its NIRSpec at Comet 3I/ATLAS on August 6, 2025, capturing this stunning image and a wealth of spectral data.
According to Domagal-Goldman:
“Infrared light is especially good at helping us understand the composition of objects. We can see little molecular fingerprints from the materials that objects are made of.”
Infrared illuminates features that would be invisible to the human eye. Webb’s observation revealed:
- High levels of carbon dioxide
- Evidence of water ice
- Molecular patterns indicating a rich, varied composition
The comet was then followed by NASA’s SPHEREx mission from August 7 to August 15-after JWST. SPHEREx undertakes infrared all-sky surveys and is well-suited for the detection of chemical signatures.
The week-long tracking yielded:
- Confirmation of CO₂ abundance
- More evidence of water-rich ice
- Data suggesting active sublimation as the comet warmed
Because JWST is able to observe faint objects even as they move far from the Sun, NASA projects it will be the last telescope capable of imaging 3I/ATLAS as it exits the Solar System.
Lucy and Psyche: Expressing Contrasting Perspectives
Two Asteroid Missions, One Interstellar Opportunity
NASA’s Psyche spacecraft, bound for the metal-rich asteroid 16 Psyche, happened upon a front-row seat for the comet’s passage. Between Sept. 8-9, 2025, Psyche photographed 3I/ATLAS from a distance of about 33 million miles. The spacecraft watched it for a total of eight hours–long enough to gather valuable positional and brightness data.
Just one week later, NASA’s Lucy mission, intended to study Trojan asteroids, caught the comet too. On the opposite side of the Solar System from Psyche, Lucy snapped 3I/ATLAS from a distance of 240 million miles.
These contrasting views by Psyche and Lucy, respectively, allow researchers to:
- Map the comet’s three-dimensional shape in better detail
- Measure its rotational behavior
- Track how its coma and tail shift over time
Taken together, these views form a stereoscopic dataset rarely achievable with interstellar objects.
Close Encounters of the Martian Kind
Mars Orbiters and Rovers Join the Effort
Although 3I/ATLAS will not come near Earth, it will pass within 19 million miles of Mars, providing an excellent opportunity for NASA’s Martian fleet to observe it relatively nearby.
MAVEN and HiRISE Observations
NASA’s MAVEN spacecraft, using its spectrograph that separates ultraviolet light into wavelengths, captured UV images. According to Tom Statler, a scientist at NASA, the separation between colors helps in identifying the existence of elements such as hydrogen.
From MAVEN’s ultraviolet data, researchers detected:
- Varying hydrogen levels in Mars’ atmosphere
- Hydrogen in the outer coma of the comet
These findings represent another piece of the puzzle regarding 3I/ATLAS’s chemical composition.
Surface Views from Mars Rovers
Although the view was faint, owing to distance, the Perseverance rover on Mars still managed to capture an image of the comet streaking across the Martian sky. Observations also included attempts by the Curiosity rover, further building up the cross-planet dataset.
Understanding Comet Origin and Age
When Did It Arrive, and How Old Is It?
NASA continues to analyze the voluminous multi-mission data returned so far; still, one of the critical scientific questions remains: When did the comet first enter the Solar System?
Preliminary results from the Swift mission indicate that Comet 3I/ATLAS could have entered the Solar System as early as May 2025, but since interstellar objects move very quickly and analyses involve complex modeling, the estimate would require more data to confirm its accuracy.
How Old Is Comet 3I/ATLAS?
Determining the age of the comet is far more complex. Interstellar comets are likely to have originated in the icy edges of other star systems, areas not unlike our own Oort Cloud. Some of this material can be older than the Solar System, which formed around 4.6 billion years ago.
There is circumstantial evidence that 3I/ATLAS could be older than our Sun, but:
- More compositional data is needed.
- Further modeling needs to be done
- Variation in molecular signatures is something that researchers need to investigate.
Until then, its age will remain as one of the intriguing mysteries regarding this celestial wanderer.
Why 3I/ATLAS Matters
A Rare Chance to Study Another Solar System Up Close
Each such interstellar visitor presents scientists with a brief but a transformative opportunity. Unlike objects that formed alongside Earth, Jupiter, and the Sun, interstellar comets carry chemical clues from distant planetary systems.
The study of 3I/ATLAS helps researchers:
Compare the chemical composition among star systems. Understand how water and organics form under various conditions. Improve models on interstellar travel and stability of comets Track gravitational interactions between objects as they enter or leave the Solar System 3I/ATLAS is not merely a visitor, but a messenger bearing ancient material from another corner of the galaxy. Looking Ahead More discoveries are expected in the coming months. The data collected so far are still being analyzed by NASA, and scientists expect a number of new insights to emerge over the months ahead. With so many missions taking imagery and making measurements, the comet represents a rare multi-point science case that provides layers of information beyond what any single telescope could provide. As the comet continues its outbound journey and eventually disappears into deep space, the data it leaves behind will shape our understanding of interstellar objects for years to come. The universe may be vast and mysterious, but through missions like these, we continue peeling back its layers-one interstellar visitor at a time.
